Canadian scientists helps debunk controversial 'arsenic life' theory

Tuesday, July 10, 2012

By Margaret Munro, Postmedia News

Microbiologist Rosie Redfield is seen in her lab at the University of B.C. in Vancouver in this undated file photo. She has been at the forefront of debunking a theory that life could exist based on arsenic instead of phosphorus.

Photographed by:Nature and Martin Dee handout, Postmedia News

Two of the biggest players in the research world — NASA and the journal Science — were wrong when they told the world that microbes scooped from a California lake had rewritten the rules of life.

In what is being described as a case of "serial failure," they took shoddy research, and overhyped it.

"It was a cascade of human failures," says Rosie Redfield of the University of British Columbia, who heads one of two research teams who disproved the original claims in new research published this week.

It documents problems with the now-infamous "arsenic life" study funded by NASA and published in Science in 2010, which was promoted as a discovery that appeared to change the chemical rules of life and had profound implications for the search for life on other planets.

On Sunday the journal Science issued an editorial statement saying the 2010 claims and reports were incorrect. The rules of life, it says, remain unbroken.

And it published the follow-up studies by Redfield's team and a second group in Europe that disproves the original claim that bacteria from California's Lake Mono could swap phosphorus with arsenic in its DNA and proteins.

"Contrary to an original report, the new research clearly shows that the bacterium, GFAJ-1, cannot substitute arsenic for phosphorus to survive," the Science statement says.

The initial 2010 study, led by researcher Felisa Wolfe-Simon, then a fellow in NASA's astrobiology program, reported that bacteria from Mono Lake appeared to be the first known exception to the rule that life requires six essential elements: oxygen, carbon, nitrogen, hydrogen, sulfur and phosphorus.

Wolfe-Simon reported that she had coaxed the bacteria GFAJ-1 in the lab to substitute arsenic for phosphorus in key molecules such as DNA and proteins. NASA and Science called a press conference to announce the discovery, saying it had big implications for the search for extraterrestrial life.

In its statement Sunday, timed to coincide with a talk Redfield gave at a conference in Ottawa, Science's editors say: "The new research shows that GFAJ-1 does not break the long-held rules of life, contrary to how Wolfe-Simon had interpreted her group's data." NASA's Astrobiology Institute, which funded the initial research, had no comment Monday.

Many researchers assailed the arsenic life study soon after it was published with Redfield leading the way on her blog.

Redfield posted a scathing critique of Wolfe-Simon's study. "Basically, it doesn't present any convincing evidence that arsenic has been incorporated into DNA," she wrote.

Redfield decided to try replicate the U.S. findings in her UBC lab, documenting her progress on her blog, RRResearch, and inviting other scientists to help.

She then teamed up with scientists at Princeton University, resulting in this week's publication in Science that indicate the growth medium in Wolfe-Simon's original experiments were contaminated.

Redfield describes the long-running controversy as the "arsenic life debacle." It entailed a series of failures started with a scientist "in love with her hypothesis," senior authors and supervisors who failed to provide adequate oversight and direction, and editors and NASA who failed to pick up on the many "red flags" in the study before it was published, Redfield told Postmedia News on Monday.

Redfield, who was busy tweeting about the latest developments, says it is heartening the way social media and scientists have helped set the record straight.

There has been glory — Redfield was named one of the world's top science newsmakers in 2011 for her "remarkable experiment in open science" as she worked to try replicate the "arsenic life" experiment in her spare time.

But it has not as yet done much to improve the fortunes of her UBC lab. Redfield says her funding from the Canadian Institutes of Health Research runs out in September.

Like many scientists, Redfield says she will head to Parliament Hill on Tuesday to protest recent cuts to federal science programs and funding.